facing process crash issue for multiple simultaneous transacion.

I am facing a issue with Artix/C++ web service. We have one web service module that is written in C++.

Module simply receive a request and send to some other interface. and receive the response and send back to corresponding request.

When we are trying one request at a time, it is working fine.. we can say that it is working fine with sequential requests.

But when we try multiple request simultaneously then core is coming.. the strange thing is that core is coming on differnet place every time and pointing to some artix like things when we try debug using dbx.